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Most Olympic-class Dutch athletes nudged Vitamin D levels above 30 nanograms with 2200 IU daily – RCT July 2016

The impact of 1-year vitamin D supplementation on vitamin D status in athletes: a dose-response study.

Eur J Clin Nutr. 2016 Jul 27. doi: 10.1038/ejcn.2016.133. [Epub ahead of print]
Backx EM1, Tieland M1, Maase K2, Kies AK3, Mensink M1, van Loon LJ4, de Groot LC1.
1Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
2Netherlands Olympic Committee*Netherlands Sports Confederation (NOC*NSF), Arnhem, The Netherlands.
3DSM Biotechnology Center, Delft, The Netherlands.
4NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.

VitaminDWiki Summary

The study (incorrectly) had decided that 30 nanograms was enough
They cut back the dose to those getting higher than 50 nanograms
Most sports groups have 50 nanograms as the target, not 30 nanograms
Started with 122 athletes – mostly outdoor sports
Started with vitamin D levels = 26 nanograms
  – so not much Vitamin D was needed to get to > 30 nanograms
Only 40 athletes completed the study
See also VitaminDWiki
Sports benefits from up to 50 ng(click on chart for details - 2012 meta-analysis)
Sports benefit up to 50 ng @ /is.gd/Vitdsports

Athletes are helped by vitamin D by:

  1. Faster reaction time
  2. Far fewer colds/flus during the winter
  3. Less sore/tired after a workout
  4. Fewer micro-cracks and broken bones
  5. Bones which do break heal much more quickly
  6. Increased VO2 and exercise endurance Feb 2011
  7. Indoor athletes especially need vitamin D
  8. Professional indoor athletes are starting to take vitamin D and/or use UV beds
  9. Olympic athletes have used UV/vitamin D since the 1930's
  10. The biggest gain from the use of vitamin D is by those who exercise less than 2 hours per day.
  11. Reduced muscle fatigue with 10,000 IU vitamin D daily
  12. Muscle strength improved when vitamin D added: 3 Meta-analysis
  13. Reduced Concussions
    See also: Sports and Vitamin D category 274 items

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To assess the prevalence of vitamin D deficiency in Dutch athletes and to define the required dosage of vitamin D3 supplementation to prevent vitamin D deficiency over the course of a year.
Blood samples were collected from 128 highly trained athletes to assess total 25(OH)D concentration. Of these 128 athletes, 54 male and 48 female athletes (18-32 years) were included in a randomized, double blind, dose-response study. Athletes with either a deficient (<50?nmol/l) or an insufficient (50-75 nmol/l) 25(OH)D concentration were randomly assigned to take 400, 1100 or 2200 IU vitamin D3 per day orally for 1 year. Athletes who had a total 25(OH)D concentration above 75?nmol/l at baseline continued with the study protocol without receiving vitamin D supplements. Serum total 25(OH)D concentration was assessed every 3 months, as well as dietary vitamin D intake and sunlight exposure.
Nearly 70% of all athletes showed an insufficient (50-75 nmol/l) or a deficient (<50 nmol/l) 25(OH)D concentration at baseline. After 12 months, serum 25(OH)D concentration had increased more in the 2200 IU/day group (+50±27 nmol/l) than the sufficient group receiving no supplements (+4±17 nmol/l; P<0.01) and the 1100 IU/day group (+25±23 nmol/l; P<0.05). Supplementation with 2200 IU/day vitamin D resulted in a sufficient 25(OH)D concentration in 80% of the athletes after 12 months.
Vitamin D deficiency is highly prevalent in athletes. Athletes with a deficient or an insufficient 25(OH)D concentration can achieve a sufficient 25(OH)D concentration within 3 months by taking 2200 IU/day.

PMID: 27460266